This invention relates generally to the repair and modification of printed circuit boards. More specifically, an automated system is presented which allows an operator to program instructions into a keyboard which cause machine operations to be carried out relative to printed circuit boards.
Printed circuit boards may need modification for any one of several reasons. There can be a design deficiency which requires correction. Rework may be desired to accommodate performance of new functions. Engineering change notices may be received specifying that corrective action be taken.
In the prior art, the U.S. Pat. No. 4,469,553 to Whitehead defines a system for manufacturing, changing, repairing and testing printed circuit boards. An automated system is described which guides an operator through each step in a series by sequentially projecting a visual image of what he must do next. This approach is premised on the assumption that it is necessary to assemble, modify, repair and/or test a complex printed circuit board in accordance with a specified schedule. The prior art system of Whitehead includes a work station on which a printed circuit board is fixedly positioned for assembly of components. All components are arranged in a predetermined array situated adjacent the work station. Structure is provided for both visual image and verbal instructions as to how the system operator is to proceed. Each step of the assembly procedure is defined and the precise location identified for placement of the next component selected from the component array.
In implementing engineering change notices Whitehead teaches that a set of visible images and corresponding verbal instructions are to be generated with respect to making new conducting paths between predetermined points on the printed circuit board. The new circuit paths may comprise the addition of lengths of insulated wire between predetermined points on the board. Additionally, the Whitehead apparatus may be used for repair of defective boards by first making tests to find the defective components, then proceeding as though implementing a change notice.
Applicants' apparatus for changing and repairing printed circuit boards does not use the image projection and verbal instruction concept of Whitehead. Rather, automated tools are directed to implement changes at X-Y printed circuit board coordinate locations indexed from a known reference point.